1. Field of the Invention
The present invention relates to a linear guide apparatus attached to machines or apparatuses such as machine tools, measuring apparatuses or the like, having a linearly movable portion, to support and guide such movable portion, and more particularly, it relates to a linear guide apparatus previously including lateral pushing means so as to be easily attached to such machines or the like.
2. Related Background Art
As shown in FIG. 8, in an example of a linear guide apparatus, sliders 2 each having an inverted U-shaped cross-section slidably ride on two corresponding guide rails 1 secured to a bed Be which is a base of a machine by bolts, so that the sliders 2 can be smoothly shifted by the rotation of rolling bodies (such as balls or rollers) received in rolling body receiving grooves formed in opposed surfaces of the guide rails 1 and of the sliders 2. The sliders 2 are generally secured to a table Ta of the machine which is an attachment member by bolts.
In attaching the linear guide apparatus to the machine, in order to ensure the attaching accuray, steps and/or recesses are previously formed in the bed Be and/or table Ta of the machine, and side surfaces (reference surfaces) s of the guide rails 1 and/or sliders 2 are laterally abutted against side surfaces S of the steps and/or recesses, thereby preventing the deviation of the rails and sliders due to the shock or impact applied thereto.
In the past, lateral pushing plates have been used as the lateral pushing means, as shown in FIGS. 9 to 11 in detail.
In the lateral pushing means shown in FIG. 9, there are formed steps 3a, 3b on the table Ta and the bed Be of the machine, each of which steps has a width such that the side surfaces of the guide rail 1 and the slider 2 to be laterally pushed are slightly protruded outwardly. As shown in FIG. 9, lateral pushing plates 5a, 5b each having a flank portion 4 are abutted against the side surfaces of the table and the bed and are secured to the latter by bolts 6a, 6b, thereby urged the guide rail 1 and the slider 2 laterally.
In the lateral pushing means shown in FIG. 10, a recess 7b having a width slightly greater than that of the guide rail 1 is formed in the bed Be, and a recess 7a having a width slightly greater than that of the slider 2 is formed in the table Ta. The guide rail 1 and the slider 2 are freely housed in the recesses 7b, 7a in registration with one sides of the latter and lateral pushing bolts 9b, 9a threaded into threaded holes formed in banks 8b, 8a of the recesses 7b, 7a are tightened, thereby urging the guide rail 1 and the slider 2 laterally in the recesses 7b, 7a of the bed Be and the table Ta.
In the lateral pushing means shown in FIG. 11, recesses 10a, 10b having widths considerably greater than those of the slider 2 and the guide rail 1, respectively, are formed in the table Ta and the bed Be, respectively. The slider 2 and the guide rail 1 are freely housed in the recesses 10a, 10b in registration with one sides of the latter. Flat lateral pushing spacers 11a, 11b having widths slightly greater than the remaining widths of the recesses 10a, 10b, respectively, are prepared. Then, the ends of the spacers are polished or filed to match the remaining recesses and are fitted into the remaining recesses 10a, 10b. Thereafter, the spacers are fixed to the table and the bed by bolts 12a, 12b.
However, in the above-mentioned linear guide apparatuses, the lateral pushing means used to correctly attach the guide rails 1 and the sliders 2 to the aimed machine with high accuracy was not involved in the linear guide apparatus. Thus, an operator must prepare lateral pushing members such as lateral pushing plates, lateral pushing bolts, lateral pushing spacers and the like, and must provide threaded holes in the table Ta and the bed Be by machining operation, for attaching these lateral pushing members to the table and the bed.
Accordingly, it is necessary for the operator to prepare the lateral pushing members independently from the linear guide apparatus, and it is troublesome to control and design such lateral pushing members and to attach such lateral pushing members to the machine. Further, there arises a problem that much labor and cost are required to provide a plurality of small threaded holes in the large-sized machine and to work the lateral pushing members themselves.
On the other hand, since machines manufactured by makers have various spaces for attaching the linear guide apparatus, it is difficult to standardize the lateral pushing members.
Furthermore, since the side surfaces (reference surfaces) s of the guide rails 1 and the sliders 2 of the linear guide apparatus are directly abutted against the reference side surfaces S of the steps 3 or the recesses 7, 10 formed on the machine by the machining operation, if the working accuracy for the side surfaces of the steps or the recesses is low, the attaching accuracy (for example, straightness, parallelism and the like) for the linear guide apparatus is badly affected. In this case, to enhance the straightness and the parallelism, the reference side surfaces of the machine must be worked with the predetermined high accuracy or more, thus increasing the labor and cost.